Abstract:

Objective To establish a candidate reference measurement procedure for serum aldosterone by isotope dilution liquid chromatography-tandem mass spectrometry（ID-LC-MS/MS）. Methods The sample was prepared by liquid-liquid extraction with methyltert-bytylether as extractant. The aldosterone-²H₇ was selected as internal standard. Samples were prepared by liquid-liquid extraction,and aldosterone was detected by ID-LC-MS/MS in negative ion mode. The basic analysis performance of the established candidate reference measurement procedure,including accuracy,precision,sensitivity and linearity,was evaluated. Results The linear range of aldosterone was 0.08-3.55 nmol/L. The limit of detection and the limit of quantitation were （LOQ）0.012 nmol/L and 0.045 nmol/L,respectively. The within-run coefficients of variation（CV） was <5.0%,and the between-run CV was <4.1%. The average recovery rates were 98.52%-100.14%. The bias of the International Federation of Clinical Chemistry and Laboratory Medicine External Quality Assessment Scheme for Reference Laboratories in Laboratory Medicine（RELA） was <1.6%. Conclusions The established ID-LC-MS/MS for detecting aldosterone in serum is accuracy and precise,and may be used as a candidate reference measurement procedure.

Key words: Aldosterone, Isotope dilution liquid chromatography-tandem mass spectrometry, Reference method